Ethylene oxide is the chief precursor to ethylene glycol and other high volume chemicals as well as being used in sterilization procedures.
Ethylene oxide is produced by oxidation of ethylene with oxygen, typically using a modified silver catalyst at 200-300° C. Often chemical modifiers such as chlorine are also included. Pressures used are in the region of 1-2 MPa. The typical yield for this reaction under industrial conditions is 70-80%. Approximately 15,000,000,000 kg are produced annually.
Most ethylene oxide is consumed as the precursor to ethylene glycol as well as a variety of other chemicals. Ethylene glycol is more commonly known for its use as an automotive coolant and antifreeze. Other chemical applications include the production of ethanolamine, diverse surfactants, and glycol ethers such as ethoxyethanol. Ethylene oxide is a highly reactive chemical due to the ease of opening of its highly strained three-membered ring, the bond being weaker than ether and the molecule less stable.